JOURNAL 



OF 



NATURAL PHILOSOPHY, CHEMISTRY, 



AND 



THE ARTS. 



JULY, 1805. 



' i. 



ARTICLE L 



Hcmarks on the. Efiimation of the Strength of Horfes. In a Let^^ 

 terfrom Mr. O. GregorYj of the Royal Military Academi/, 

 Woolwich, 



To Mr. NICFIOLSON. 

 SIR, 



A HE remarks of your Ingenious correfpondent, Mr. Horn -Reference to 

 blower, on the various eftimates of the Power of a Horfe, and:^^/* ^p^g"^^^"^' 

 the abfurdity of adopting a quantity fo flucluating and fo dif-horfe powers, 

 ficult to afcertaiti, as a common meafure by which the powers 

 and effcfts of (learn engines and other machines are to be efti- 

 mated and compared, have induced me to throw together a 

 few obfervations on the fame fubjeds; the theoretic part of 

 which, though familiar to moil men of fcience, feems not to 

 be always known, or at leaft recollefted, by fome perfons who 

 arc employed in the pradice; and which are altogether much 

 at your fervice for infertion in the Journal, if you think them 

 likely to be oF any utility. 



Dr. Defaguliers lias given another eftimate of the labour of Eftiraate of 

 ahorfe, befide that mentioned by Mr. Hornblower, and wbich j^^'J-ggyj'j^" 

 indeed does not feem very confident with it ; for in vol. II. p. aoolb. eight 

 251 .of his Experimental Philofophy, he affirms that a horfe in a^^x^s^er 



Vol. XI. — July, 1805. L an hour j or 3* feet 



per fecond. 



